Hydroboost Steering Box Help

[48cj2a]

Having an issue with my 85 CUCV M-1009 (Blazer)

There is a 1/4 play either direction with the wheel before the steering actually moves. Driving you must constantly steer left to right to stay going straight as it is wondering.

Today I swapped steering boxes with another hydroboost truck but his one was a gas 1 ton vs my military rated 3/4 diesel. At first start it would not pwr steer at all so I checked the p/s fluid and it was nearly empty so I filled it and although I did not actually drive it it feels no different. backing up and pulling forward. When I shut it off it started overflowing foamy p.s fluid.

Is there a difference between gas/diesel steering boxes? the casting numbers on the boxes were identical. Looking down the hole of the non pressure side looked like a check valve might have been in it. Is this correct?

[hatzie]

It could be the ball joints or tie rods.
Jack up the whole front end and set the axle tubes on jack-stands to check stuff out.
Have an assistant turn the steering wheel. Does the rag joint turn 1/4 rev before the pitman arm moves? Is the joint on the pitman arm hammered?
Ball joints... Is there any play rocking either wheel with your hands at 90 degrees to the road?
Tie rods... When rocking the wheels paralell to the road does one wheel move before the other or do you feel play in the joints that's not wheel bearings?

[scotties truck]

x2 on that

[hatzie]

The foam is normal. You cracked the system open so the booster needs to be bled out.
Gas and diesel hydroboost boxes should be the same.
The civvy 1ton prolly has more miles than your M1009. Unless your old box has a bunch of play I'd put it back on.

[48cj2a]

Thanks Guys!

I kind of figured on the the foaming but the thing being empty (which seems right - the 1 ton was probably empty and took all the reserve) but why did it boil over so to speak?

Both vehicles only have 4X,XXX mile and their condition makes be believe the od's are correct.

I'll support the axle as described and check the suggested componets.

[powerdriver 1958]

Originally Posted by 48cj2a

Thanks Guys!
but why did it boil over so to speak?

You have oil and air together so when shut off the compressed air will "spring back" .....Pretty normal when running low on fluid .

[jonessmc87]

dont forget the rag joint coupling at the steering box. the "rag" in mine was very sloppy and the holes got ovaled out and that scary play was there. i replaced it with a old corvette one i had in the basement and it fixed a lot of the slop.

[hatzie]

The Jeep XJ steering shafts can be modified to fit the 73-91 GM light trucks and eliminate the floppy rag joint. Not my Video.

YouTube - Installing XJ steering shaft in 1987...